(i) Field of the Invention
The present invention relates to an electronic device having a display and an illuminance sensor for controlling display brightness on the basis of ambient illuminance, and to a method for controlling the display brightness. The electronic device is configured to control measurement of illuminance by means of the illuminance sensor on the basis of an on-or-off state of an LED provided to the electronic device.
(ii) Description of the Related Art
A recent trend of some electronic device such as a mobile phone or a mobile data terminal is that it consumes more power as it is equipped with a display of a greater size or a processor of a higher operating frequency. Thus, a lot of electronic devices are configured to measure ambient brightness by using their illuminance sensors, and to control use of their displays with minimally required backlight brightness these days.
A mobile communication device configured to consume less power is disclosed, e.g., in Japanese Patent Publication of Unexamined Application (Kokai) No. 2005-236524. The mobile communication device of JP 2005-236524 is configured to minimize an effect of turning on and off of a light for illuminating the surroundings, and to optimize brightness levels of an operation unit and a display unit so as to consume less power. The mobile communication device of JP 2005-236524 is configured to control, as usual, a brightness level of a backlight for the operation unit in accordance with an ambient illuminance level sensed by a photosensor. If the light is turned on, though, the mobile communication device turns on the backlight for the operation unit regardless of a sensing level of the photosensor while taking an effect of the light to the sensing level of the photosensor into account.
It is generally known that an electronic device such as a mobile phone has an LED for indicating that its battery is being recharged, or that a missed call or an unread email exists. If, however, the LED and the illuminance sensor are arranged close to each other, such an arrangement may cause a problem that the illuminance sensor senses light of the LED resulting in that the backlight brightness cannot be properly controlled.
The present invention has been made in view of the above circumstances and provides electronic equipment in which the brightness of a back light is properly controlled on the basis of illuminance even when LED and an illuminance sensor are provided in proximity to each other.